the homopolymerization of tetrafluoroethylene and the copolymerization of tetrafluoroethylene with very small amounts of ethylenically unsaturated comonomers in aqueous medium can be carried out by two distinctly different procedures. In one procedure, called suspension polymerization, little or no dispersing agent is employed and agitation is carried out vigorously in order to produce a precipitated resin, commonly referred to as "granular" resin. In the other procedure, sufficient dispersing agent is employed and agitation is mild in order to produce small colloidal size particles dispersed in the aqueous reaction medium. In this second procedure, called aqueous dispersion polymerization, precipitation (i.e., coagulation) of the resin particles is avoided. The two procedures produce distinctly different products. The granular product can be molded in various forms, whereas the resin produced by the aqueous dispersion method cannot be molded but is fabricated by dispersion coating or by converting to powder for paste extrusion with a lubricating medium. In contrast, the granular resin is incapable of being paste extruded or dispersion coated.
However, even in the suspension polymerization procedure, presence of small amounts of dispersing agent are sometimes beneficial to increase the surface area of the granular polymer particles produced. See, for example, Anderson, U.S. Pat. No. 3,245,972, when in Example VI, use of 300 ppm ammonium perfluorooctanoate, CF.sub.3 --CF.sub.2 --.sub.6 COONH.sub.4, is taught. Use of other dispersing agents with additional beneficial properties has long been a research goal.